diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-13 15:51:06 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-13 15:51:06 -0700 |
commit | ca4e7c51201fc47b2668d58faaa3b46a99d1a233 (patch) | |
tree | 06e0ece281eff94ff78c11e78e036d5b61ebbe60 /drivers/clk/clk-si544.c | |
parent | daf3ef6e965d1d51d6ec604a8fc9919b75d5ec3c (diff) | |
parent | b44c4ddf4a15c42a91a88aaa32b7d53cf43391cb (diff) |
Merge tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk updates from Stephen Boyd:
"The large diff this time around is from the addition of a new clk
driver for the TI Davinci family of SoCs. So far those clks have been
supported with a custom implementation of the clk API in the arch port
instead of in the CCF. With this driver merged we're one step closer
to having a single clk API implementation.
The other large diff is from the Amlogic clk driver that underwent
some major surgery to use regmap. Beyond that, the biggest hitter is
Samsung which needed some reworks to properly handle clk provider
power domains and a bunch of PLL rate updates.
The core framework was fairly quiet this round, just getting some
cleanups and small fixes for some of the more esoteric features. And
the usual set of driver non-critical fixes, cleanups, and minor
additions are here as well.
Core:
- Rejig clk_ops::init() to be a little earlier for phase/accuracy ops
- debugfs ops macroized to shave some lines of boilerplate code
- Always calculate the phase instead of caching it in clk_get_phase()
- More __must_check on bulk clk APIs
New Drivers:
- TI's Davinci family of SoCs
- Intel's Stratix10 SoC
- stm32mp157 SoC
- Allwinner H6 CCU
- Silicon Labs SI544 clock generator chip
- Renesas R-Car M3-N and V3H SoCs
- i.MX6SLL SoCs
Removed Drivers:
- ST-Ericsson AB8540/9540
Updates:
- Mediatek MT2701 and MT7622 audsys support and MT2712 updates
- STM32F469 DSI and STM32F769 sdmmc2 support
- GPIO clks can sleep now
- Spreadtrum SC9860 RTC clks
- Nvidia Tegra MBIST workarounds and various minor fixes
- Rockchip phase handling fixes and a memory leak plugged
- Renesas drivers switch to readl/writel from clk_readl/clk_writel
- Renesas gained CPU (Z/Z2) and watchdog support
- Rockchip rk3328 display clks and rk3399 1.6GHz PLL support
- Qualcomm PM8921 PMIC XO buffers
- Amlogic migrates to regmap APIs
- TI Keystone clk latching support
- Allwinner H3 and H5 video clk fixes
- Broadcom BCM2835 PLLs needed another bit to enable
- i.MX6SX CKO mux fix and i.MX7D Video PLL divider fix
- i.MX6UL/ULL epdc_podf support
- Hi3798CV200 COMBPHY0 and USB2_OTG_UTMI and phase support for eMMC"
* tag 'clk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: (233 commits)
clk: davinci: add a reset lookup table for psc0
clk: imx: add clock driver for imx6sll
dt-bindings: imx: update clock doc for imx6sll
clk: imx: add new gate/gate2 wrapper funtion
clk: imx: Add CLK_IS_CRITICAL flag for busy divider and busy mux
clk: cs2000: set pm_ops in hibernate-compatible way
clk: bcm2835: De-assert/assert PLL reset signal when appropriate
clk: imx7d: Move clks_init_on before any clock operations
clk: imx7d: Correct ahb clk parent select
clk: imx7d: Correct dram pll type
clk: imx7d: Add USB clock information
clk: socfpga: stratix10: add clock driver for Stratix10 platform
dt-bindings: documentation: add clock bindings information for Stratix10
clk: ti: fix flag space conflict with clkctrl clocks
clk: uniphier: add additional ethernet clock lines for Pro4
clk: uniphier: add SATA clock control support
clk: uniphier: add PCIe clock control support
clk: Add driver for the si544 clock generator chip
clk: davinci: Remove redundant dev_err calls
clk: uniphier: add ethernet clock control support for PXs3
...
Diffstat (limited to 'drivers/clk/clk-si544.c')
-rw-r--r-- | drivers/clk/clk-si544.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/drivers/clk/clk-si544.c b/drivers/clk/clk-si544.c new file mode 100644 index 000000000000..1c96a9f6c022 --- /dev/null +++ b/drivers/clk/clk-si544.c @@ -0,0 +1,411 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for Silicon Labs Si544 Programmable Oscillator + * Copyright (C) 2018 Topic Embedded Products + * Author: Mike Looijmans <mike.looijmans@topic.nl> + */ + +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +/* I2C registers (decimal as in datasheet) */ +#define SI544_REG_CONTROL 7 +#define SI544_REG_OE_STATE 17 +#define SI544_REG_HS_DIV 23 +#define SI544_REG_LS_HS_DIV 24 +#define SI544_REG_FBDIV0 26 +#define SI544_REG_FBDIV8 27 +#define SI544_REG_FBDIV16 28 +#define SI544_REG_FBDIV24 29 +#define SI544_REG_FBDIV32 30 +#define SI544_REG_FBDIV40 31 +#define SI544_REG_FCAL_OVR 69 +#define SI544_REG_ADPLL_DELTA_M0 231 +#define SI544_REG_ADPLL_DELTA_M8 232 +#define SI544_REG_ADPLL_DELTA_M16 233 +#define SI544_REG_PAGE_SELECT 255 + +/* Register values */ +#define SI544_CONTROL_RESET BIT(7) +#define SI544_CONTROL_MS_ICAL2 BIT(3) + +#define SI544_OE_STATE_ODC_OE BIT(0) + +/* Max freq depends on speed grade */ +#define SI544_MIN_FREQ 200000U + +/* Si544 Internal oscilator runs at 55.05 MHz */ +#define FXO 55050000U + +/* VCO range is 10.8 .. 12.1 GHz, max depends on speed grade */ +#define FVCO_MIN 10800000000ULL + +#define HS_DIV_MAX 2046 +#define HS_DIV_MAX_ODD 33 + +/* Lowest frequency synthesizeable using only the HS divider */ +#define MIN_HSDIV_FREQ (FVCO_MIN / HS_DIV_MAX) + +enum si544_speed_grade { + si544a, + si544b, + si544c, +}; + +struct clk_si544 { + struct clk_hw hw; + struct regmap *regmap; + struct i2c_client *i2c_client; + enum si544_speed_grade speed_grade; +}; +#define to_clk_si544(_hw) container_of(_hw, struct clk_si544, hw) + +/** + * struct clk_si544_muldiv - Multiplier/divider settings + * @fb_div_frac: integer part of feedback divider (32 bits) + * @fb_div_int: fractional part of feedback divider (11 bits) + * @hs_div: 1st divider, 5..2046, must be even when >33 + * @ls_div_bits: 2nd divider, as 2^x, range 0..5 + * If ls_div_bits is non-zero, hs_div must be even + */ +struct clk_si544_muldiv { + u32 fb_div_frac; + u16 fb_div_int; + u16 hs_div; + u8 ls_div_bits; +}; + +/* Enables or disables the output driver */ +static int si544_enable_output(struct clk_si544 *data, bool enable) +{ + return regmap_update_bits(data->regmap, SI544_REG_OE_STATE, + SI544_OE_STATE_ODC_OE, enable ? SI544_OE_STATE_ODC_OE : 0); +} + +/* Retrieve clock multiplier and dividers from hardware */ +static int si544_get_muldiv(struct clk_si544 *data, + struct clk_si544_muldiv *settings) +{ + int err; + u8 reg[6]; + + err = regmap_bulk_read(data->regmap, SI544_REG_HS_DIV, reg, 2); + if (err) + return err; + + settings->ls_div_bits = (reg[1] >> 4) & 0x07; + settings->hs_div = (reg[1] & 0x07) << 8 | reg[0]; + + err = regmap_bulk_read(data->regmap, SI544_REG_FBDIV0, reg, 6); + if (err) + return err; + + settings->fb_div_int = reg[4] | (reg[5] & 0x07) << 8; + settings->fb_div_frac = reg[0] | reg[1] << 8 | reg[2] << 16 | + reg[3] << 24; + return 0; +} + +static int si544_set_muldiv(struct clk_si544 *data, + struct clk_si544_muldiv *settings) +{ + int err; + u8 reg[6]; + + reg[0] = settings->hs_div; + reg[1] = settings->hs_div >> 8 | settings->ls_div_bits << 4; + + err = regmap_bulk_write(data->regmap, SI544_REG_HS_DIV, reg, 2); + if (err < 0) + return err; + + reg[0] = settings->fb_div_frac; + reg[1] = settings->fb_div_frac >> 8; + reg[2] = settings->fb_div_frac >> 16; + reg[3] = settings->fb_div_frac >> 24; + reg[4] = settings->fb_div_int; + reg[5] = settings->fb_div_int >> 8; + + /* + * Writing to SI544_REG_FBDIV40 triggers the clock change, so that + * must be written last + */ + return regmap_bulk_write(data->regmap, SI544_REG_FBDIV0, reg, 6); +} + +static bool is_valid_frequency(const struct clk_si544 *data, + unsigned long frequency) +{ + unsigned long max_freq = 0; + + if (frequency < SI544_MIN_FREQ) + return false; + + switch (data->speed_grade) { + case si544a: + max_freq = 1500000000; + break; + case si544b: + max_freq = 800000000; + break; + case si544c: + max_freq = 350000000; + break; + } + + return frequency <= max_freq; +} + +/* Calculate divider settings for a given frequency */ +static int si544_calc_muldiv(struct clk_si544_muldiv *settings, + unsigned long frequency) +{ + u64 vco; + u32 ls_freq; + u32 tmp; + u8 res; + + /* Determine the minimum value of LS_DIV and resulting target freq. */ + ls_freq = frequency; + settings->ls_div_bits = 0; + + if (frequency >= MIN_HSDIV_FREQ) { + settings->ls_div_bits = 0; + } else { + res = 1; + tmp = 2 * HS_DIV_MAX; + while (tmp <= (HS_DIV_MAX * 32)) { + if (((u64)frequency * tmp) >= FVCO_MIN) + break; + ++res; + tmp <<= 1; + } + settings->ls_div_bits = res; + ls_freq = frequency << res; + } + + /* Determine minimum HS_DIV by rounding up */ + vco = FVCO_MIN + ls_freq - 1; + do_div(vco, ls_freq); + settings->hs_div = vco; + + /* round up to even number when required */ + if ((settings->hs_div & 1) && + (settings->hs_div > HS_DIV_MAX_ODD || settings->ls_div_bits)) + ++settings->hs_div; + + /* Calculate VCO frequency (in 10..12GHz range) */ + vco = (u64)ls_freq * settings->hs_div; + + /* Calculate the integer part of the feedback divider */ + tmp = do_div(vco, FXO); + settings->fb_div_int = vco; + + /* And the fractional bits using the remainder */ + vco = (u64)tmp << 32; + do_div(vco, FXO); + settings->fb_div_frac = vco; + + return 0; +} + +/* Calculate resulting frequency given the register settings */ +static unsigned long si544_calc_rate(struct clk_si544_muldiv *settings) +{ + u32 d = settings->hs_div * BIT(settings->ls_div_bits); + u64 vco; + + /* Calculate VCO from the fractional part */ + vco = (u64)settings->fb_div_frac * FXO; + vco += (FXO / 2); + vco >>= 32; + + /* Add the integer part of the VCO frequency */ + vco += (u64)settings->fb_div_int * FXO; + + /* Apply divider to obtain the generated frequency */ + do_div(vco, d); + + return vco; +} + +static unsigned long si544_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_si544 *data = to_clk_si544(hw); + struct clk_si544_muldiv settings; + int err; + + err = si544_get_muldiv(data, &settings); + if (err) + return 0; + + return si544_calc_rate(&settings); +} + +static long si544_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct clk_si544 *data = to_clk_si544(hw); + struct clk_si544_muldiv settings; + int err; + + if (!is_valid_frequency(data, rate)) + return -EINVAL; + + err = si544_calc_muldiv(&settings, rate); + if (err) + return err; + + return si544_calc_rate(&settings); +} + +/* + * Update output frequency for "big" frequency changes + */ +static int si544_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_si544 *data = to_clk_si544(hw); + struct clk_si544_muldiv settings; + int err; + + if (!is_valid_frequency(data, rate)) + return -EINVAL; + + err = si544_calc_muldiv(&settings, rate); + if (err) + return err; + + si544_enable_output(data, false); + + /* Allow FCAL for this frequency update */ + err = regmap_write(data->regmap, SI544_REG_FCAL_OVR, 0); + if (err < 0) + return err; + + + err = si544_set_muldiv(data, &settings); + if (err < 0) + return err; /* Undefined state now, best to leave disabled */ + + /* Trigger calibration */ + err = regmap_write(data->regmap, SI544_REG_CONTROL, + SI544_CONTROL_MS_ICAL2); + if (err < 0) + return err; + + /* Applying a new frequency can take up to 10ms */ + usleep_range(10000, 12000); + + si544_enable_output(data, true); + + return err; +} + +static const struct clk_ops si544_clk_ops = { + .recalc_rate = si544_recalc_rate, + .round_rate = si544_round_rate, + .set_rate = si544_set_rate, +}; + +static bool si544_regmap_is_volatile(struct device *dev, unsigned int reg) +{ + switch (reg) { + case SI544_REG_CONTROL: + case SI544_REG_FCAL_OVR: + return true; + default: + return false; + } +} + +static const struct regmap_config si544_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .cache_type = REGCACHE_RBTREE, + .max_register = SI544_REG_PAGE_SELECT, + .volatile_reg = si544_regmap_is_volatile, +}; + +static int si544_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct clk_si544 *data; + struct clk_init_data init; + int err; + + data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + init.ops = &si544_clk_ops; + init.flags = 0; + init.num_parents = 0; + data->hw.init = &init; + data->i2c_client = client; + data->speed_grade = id->driver_data; + + if (of_property_read_string(client->dev.of_node, "clock-output-names", + &init.name)) + init.name = client->dev.of_node->name; + + data->regmap = devm_regmap_init_i2c(client, &si544_regmap_config); + if (IS_ERR(data->regmap)) + return PTR_ERR(data->regmap); + + i2c_set_clientdata(client, data); + + /* Select page 0, just to be sure, there appear to be no more */ + err = regmap_write(data->regmap, SI544_REG_PAGE_SELECT, 0); + if (err < 0) + return err; + + err = devm_clk_hw_register(&client->dev, &data->hw); + if (err) { + dev_err(&client->dev, "clock registration failed\n"); + return err; + } + err = devm_of_clk_add_hw_provider(&client->dev, of_clk_hw_simple_get, + &data->hw); + if (err) { + dev_err(&client->dev, "unable to add clk provider\n"); + return err; + } + + return 0; +} + +static const struct i2c_device_id si544_id[] = { + { "si544a", si544a }, + { "si544b", si544b }, + { "si544c", si544c }, + { } +}; +MODULE_DEVICE_TABLE(i2c, si544_id); + +static const struct of_device_id clk_si544_of_match[] = { + { .compatible = "silabs,si544a" }, + { .compatible = "silabs,si544b" }, + { .compatible = "silabs,si544c" }, + { }, +}; +MODULE_DEVICE_TABLE(of, clk_si544_of_match); + +static struct i2c_driver si544_driver = { + .driver = { + .name = "si544", + .of_match_table = clk_si544_of_match, + }, + .probe = si544_probe, + .id_table = si544_id, +}; +module_i2c_driver(si544_driver); + +MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>"); +MODULE_DESCRIPTION("Si544 driver"); +MODULE_LICENSE("GPL"); |